<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
            list-style: none;
        }
        textarea{
            width: 800px;
            margin: 10px auto;
            display: block;
            outline: none;
        }
        button{
            width: 800px;
            margin: 10px auto;
            display: block;
            background: orange;
            border: none;
            line-height: 40px;
            cursor: pointer;
            color: #fff;
        }
        ul{
            width: 800px;
            margin: 10px auto;
        }
        ul>li{
            background-color: olivedrab;
            margin-bottom: 10px;
            position: relative;
            padding: 4px;
        }
        span{
            position: absolute;
            right: -5px;
            top: -5px;
            cursor: pointer;
        }
    </style>
</head>
<body>
    <textarea name="" id="txt" cols="30" rows="10"></textarea>
    <button id="btn">微博发布</button>
    <ul id="box">
        <li>
            昨天打雷了
            <p>2021-06-04</p>
            <span onclick="del(this)">X</span>
        </li>
    </ul>
    <script>
        btn.onclick=function(){
            if(txt.value==''){
                alert('内容不能为空')
            }else{
            var year=d.getFullYear();
            var month=d.getMonth()+1;
            var date=d.getDate();
            var val=txt.value;
            var tag=document.createElement('li');
            tag.innerHTML=` ${val}
            <p>2021-06-04</p>
            <span>X<span>`
            box.appendChild(tag);
            txt.value='';
            }
        }

        function del(a){
            a.parentNode.parentNode.removeChild(a.parentNode)
        }
    </script>
</body>
</html>